Soriano is Piniella's problem

5 of those 6 teams are in the American League, where there is a DH and, most people feel, better overall competition. An equal staff will have a higher ERA there.

The Cubs’ bullpen overall is at best going to stay even. Howry, Wuertz and Wood have been off to slow starts and I believe, based on their track records and their stuff, that they’ll improve. Lieber has been pitching over his head to make up for those slow starts but he’s moving to the rotation for the time being. He would have come to earth anyway (based on career numbers), and now the innings he would have pitched will be pitched by a less-experienced player, so it’s hard to predict how they’ll go; he’ll go deeper into his starts than Hill, though, which will help the whole ‘pen. Marmol is off to an exceptional start but… he might just be that damn good. As for his workload, I was looking today and… in 2007 he threw 40 innings in AAA before his 69 in the majors, but most of his minor-league appearances have been starts. I have no rational basis on which to claim he either can or can’t handle the load he’s carried so far this year. Wild cards include the return of Scott Eyre, Marshall perhaps taking on more long work, and the performance of Gallagher and Fox, or anyone that replaces them if they’re sent back down. Overall, I think all this adds up to the bullpen getting only slightly worse (Lieber’s hot start will be hard to match), as long as Marmol’s arm stays attached to his body and the starters can give them all enough rest.

The rotation, however, might look considerably worse by the end. Zambrano is good, but probably not as good as his start has been based on past performance. If he keeps his walks down he may have a career year (his BABIP is a very normal .299, which says to me that his start has been due to good pitching, not luck), but he’s had a career full of hot and cold months, and that type of performance is tough to keep up even for the best pitchers. Lilly looked to have some velocity back today, and I’m inclined to think he’ll be OK. His improvement will be compensated for by Dempster’s fall-to-earth; Demp has never been anywhere near this good for a full season and his BABIP is .192 right now. Marquis has looked shaky early, having to scratch out of lots of jams, (WHIP over 1.6!) but his BABIP is .342; his walk, strikeout, and home-run rates (3.18, 5.40, 0.95 respectively per 27 outs) are slightly better than his career numbers (3.49, 5.40, 1.23), so I have hope that he can settle into an average season. He’s gotta pitch deeper into games. Since he’s been unlucky to allow lots of hits and lucky that so few have come in to score, I think his ERA is about where it will end up, but he’ll go a slight bit deeper into games on average. That is, until he runs out of gas late in the season, as he so often has. The last spot is now Lieber’s, and recent history would predict very consistent, very league-average work from him, and just over 6 innings per start. TLDR: Z down somewhat, Demp way down, Lilly up somewhat, Marquis about the same (until late) and Lieber bein’ Lieber. That adds up to the rotation giving up slightly more runs than they have to this point.

This is all my own opinion, and I speak from a position of very little authority. It assumes no injuries, no further Rich Hill sightings, and that nobody falls flat on his face or becomes suddenly amazing. None of these are necessarily good assumptions. But I think the overall analysis supports the idea that the Cubs’ pitchers overall will give up more runs per game than they have, and that their rotation really consists of one ace and four guys who are 3rd-4th starters on an average team. It isn’t a rotation that will carry an average offense to contend. It’s more realistic that the offense will carry this team to contention. Is the pitching a concern, as MDBNIU says? Well, if Wuertz, Howry, and Wood don’t pick it up, then it is a serious concern; if Lieber eats innings as a starter and Lilly looks like a solid 2-3 starter like he did today, it’s less of a concern.